C57BL/6N mice, an important strain used in NIEHS research, develop an alopecia which usually arises at 4 to 6 months of age. This condition often progresses into a protracted dermatitis and may become severe enough that the animals develop ulcerative skin lesions and suffer premature morbidity and mortality. This study was directed at discovering a nutritional basis for the progressive skin disorders. Mice were divided into groups of 15 and fed either the standard NIH-31 control diet or NIH-31 test diet fortified at three times the normal concentration with either animal tallow, menhaden oil, safflower oil, soybean oil, thiamine, riboflavin, pyridoxine, cyanocobalamin, biotin choline, vitamin E, zinc oxide or other vitamin or mineral mixtures. Mice were evaluated at 3-month intervals for quality of hair coat, alopecia, dermatitis, and skin lesions. Mice were sacrificed when initial skin lesion developed. Preliminary analysis of these results suggest that the alopecia and degenerative skin conditions were reduced in groups of mice fed the test die fortified with the B vitamins (B1, B2, B6), Vitamin E, Biotin, or Choline when compared to the groups of mice fed the control diet. After one year, the mice fed the B vitamins, Vitamin E, Choline and Biotin had healthier, thicker hair coats and more mice survived as compared to the control groups. These preliminary findings suggest that C57BL/6N mice may require dietary changes as they age to compensate for natural degenerative skin changes that occur, probably due to strain dependent genetic predisposition.